A circular field of 15 radius is surrounded by a path of width 7m then the area of path?

Ineed with number 6 , explain how to get 1978

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

If g^-1(x) is the inverse of g (x) which statement must be true